Three commonly used drainage system components, with considerably different characteristics and roles in stormwater management, were studied and reported on in this thesis: (i) grass swales, (ii) gully pots (GPs), and (iii) stormwater management ponds. With time, solids and associated pollutants accumulate in these components, and regular maintenance is needed to ensure that their design functions, including protection of the environment, are sustained.

Trace metals and their concentrations, loads and speciation were investigated within and among the individual types of components. The study program started with a critical review of processes enhancing the quality of stormwater passing over grass filter strips and through swales, and continued with field research of swale soils, and sediments from GPs and ponds.

The swales studied in the thesis served for stormwater drainage and storage of snow cleared from adjacent trafficked areas during winter months. Results suggest that both stormwater runoff and snow stored in the swale were transport vectors of metals originating from traffic. Other sources of metals were native soils and traction material used in winter road maintenance.

Moreover, the speciation results showed that across components, Zn and Pb were the metals with the highest share in the most mobile fraction, followed by Cu, while Ba, Cr,V, Co, and Ni were found in a higher share in the less mobile fractions.

GP and pond sediments showed similar organic matter content, whereas swales soils showed relatively low organic content, further decreasing with the soil depth. Results suggested that higher organic matter content corresponded to higher concentrations of certain metals in the case of ponds and, to some extent, swales. In the case of GPs, a positive relationship between metals and the proportion of fine particles was detected.

The highest concentrations of Cu and Zn were observed in sediments from ponds and reached 319 and 1380 mg/kg DW, respectively. The highest concentration of Pb (188mg/kg DW) was observed in swale, operating for 57 years located next to a road with the traffic intensity of 11,650 v/day.

The large variation in the accumulated dry mass of solids in GPs (2-91 kg) questions the current practice of emptying all GPs at the same regular intervals. Moreover, of the 26 GP samples, Swedish thresholds for soils with the sensitive (S) land use were exceeded for Cu in five samples and Zn in six samples. Of 32 pond samples, the S threshold was exceeded for Cu in nine samples and Zn in 12 samples; of these, three and eight of the pond samples also exceeded the less sensitive (LS) threshold. Of 96 swale samples, 25 samples exceeded the S threshold for Pb, with one sample also exceeding the LS threshold.